Harrow and cultivator



(No Model.) 7

G. E. DUNBAR. Harrow and Cultivator.

No. 233,663. 3 Patented Oct. 26, I880.

G.-ED7IN DUNBAR, OF KALAMAZOO, MICHIGAN.

HARROW AND CULTIVATOR.

SPECIFICATION forming part of Letters Patent No. 233,663, dated October 26, 1880,

Application filed June 22, 1880.

To all whom it may concern:

Be it known that I, G. EDWIN DUNBAR, of Kalamazoo, in the county of Kalamazoo and State of Michigan, have invented a new and valuable Improvement in Harrows and Oultivators, of which the following is a specification.

The principal objects of my invention are, first, to provide a harrow or cultivator with a combined oscillating supporting-spring and shoe, whereby greater and freer oscillation is imparted to a tooth, shank, or share engaging the ends of said spring, and the frame of the device is prevented from settling down or too closely engaging the soil; second, the connection of an oscillating supporting-spring with a tooth or share by means of a cam or semi-eccentric engagement, whereby bolts and bolt-holes are dispensed with, if desired, and the two ends of said spring shut by each other on a parallel angle, y which arrangement the tooth, when meeting an obstruction, rises directly up and back without affecting the frame, and the spring and tooth have a freer movement, where they engage each other, over other devices usingan oscillatingsupporting-spring third, the construction of a combined share and colter made all in one piece, by the peculiar form of which a downward pressure upon a sod-furrow is effected, when the colter part of the share either cuts through or holds said furrow down and allows the share portion to pass through without tearing up the furrow.

The spring and tooth, by their construction and combination, effect other minor results set forth in the following description.

In the accompanying drawings, forming a part of this specification, Figure 1 represents a portion of the frame and one spring and tooth and their connections of my improved harrow or cultivator. Fig. 2 represents one end of the spring, showing the slot before the lug is pressed over the outer end of the slot. Fig. 3 represents the circular lug for the spring. Fig. 4. represents the method of fastening the upper part of the spring in the concave dado.

In the accompanying drawings, A represents a beam of a harrow or cultivator frame. B represents the circular spring. It is slotted longitudinally at each end, as shown in Fig. 2, to admit of a tooth, shank, or share being inserted in the slots, whereby it is held up- (No model.)

right and in a position to act on the principle of a lever on the two ends of the spring.

D D represent circular lugs pressed on the spring at the outer ends of the slots. springs are cast the lugs may be cast on, or a round eye may be rolled on, the end of the spring, or the slot may be cut to the end, two eyes rolled and a bolt put through, each of which would be the equivalent of a separate lug. These lugs or theirequivalent each form an axis around which the curved indentures N N roll with very little friction. The lugs being held firmly in the curved indentures by the pressure of the spring prevents the tooth, shank. or share from fallingorbeing wrenched out. This arrangement obviates all necessity of bolt-holes in the tooth, shank, or share.

When, in operating, the point of the tooth, shank, or share is forced backward by an 0bstruction, the curved indentures in the upper If the K end of the tooth, shank, or share, and the lugs on the ends of the spring operate on the principle of a cam, the upper curved indenture pushes against the upper lug at the same time that the lower curved indenture pulls against the lower lug, thus pushing the upper end of the spring forward and pulling the lower end of it backward. WVhen its point is freed or lets go of the obstruction the recoil of the spring forces its ends beyond their natural point of rest, which, at the same time, throws the point of the tooth, shank, or share forward. of its normal position, and the friction of the connection being so slight and the spring so short it imparts to the point of the tooth, shank, or share a very rapid oscillating lllO- tion, which is continued for a much longer time than that produced by any other known device. This rapid and long-continued oscillation pulverizes the soil better than any implement heretofore produced. The rapidity of the springs recoil also forces the workingpoint of the tooth or share into the ground much quicker than a long spring-tooth will force its point. This prevents the point from skipping so much space after passing an obstruction, and constitutes a greatirnprovement. The spring will allow the point of the tooth or share to turn backward and pass an obstruction, and immediately force it back into the ground without injuring it or disturbing the working of any other part of the implement. The spring is made wide and so shaped that its front end acts as a shoe and prevents its wallowing in soft ground and loading up the frame. This is one of the valuable improvements I claim, as it holds the frame up from the ground and prevents it striking against stones and grubs, a desirable result usually produced, if at all, by wheels or separate shoes. A portion of the inside surface of the upper part of the spring is slightly corrugated r beaded, and the corrugations engage the edges of the clip or plate. This is a valuable device and serves a double purpose: First, as a gage by which to regulate the pitch of the teeth, which can be changed by loosening the nuts, rolling the spring in its fastening, and then tightening up the nuts. The teeth can all be pitched alike byhavingthesame groove in each spring engage the front end of the clip. Second, the grooves engagingthe edges of the clip or plate will. prevent the spring from slipping in its fastenings. (See Fig. for an illustration of its working.)

0 represents a colter and mold-board tooth combined. It is formed of a strip of metal, with its upper end thrown backward, and has curved indentures formed in its upper and lower edges. Its middle portion is thrown forward and then backward, by which means its front edge forms a semicircular colter, (see letter F,) which is sharpened between points 1 and 2. The colteris above and forward of the point of the tooth, and acts like the colter of a plow, cutting the crust and sod. By its peculiar shape it also prevents the point from tearing up sod on summer fallow, as it presses down upon as well as against the sod, and

' either cuts it in two or holds it down and allows the point to turn backward and clear it.

The point of the tooth is formed by halftwisting the lower end of the tooth and bending it forward, thus presenting its broad surface and V-shaped cutting-point G to the soil. The half-twist forms a mold-board. Its point being thrown forward cuts the roots of grass and weeds instead of pulling over them. The sharp colter and mold-board shape make the draft lighter than any other tooth doing equal execution. It is also so shaped that by bitchin g to the rear end of a harrow and drawing it backward the points of the teeth are so many runners to draw it off on. At the same time the friction on the points sharpens them.

E represents one of the longitudinal slots in the ends of the spring before the lug is put on.

Hrepresents the clip or plate,KKthe bolts, L one of the nuts that fasten the spring to the frame.

M represents a concave dado the width of the spring into which the upper part of the spring sets. Its sides prevent the spring from twisting.

Having described this invention, what I claim, and desire to secure by Letters Patcut, is

1. A combined circular oscillating spring and shoe, the two free ends of which shut by each other, the front half forming a section of a circle of about one-fifth greater diameter than that formed by its rear halt, the said front half operating as a gage or shoe, and the end of the said half, together with the end of the rear half, engaging with and operating a harrow or cultivator tooth, shank, or share by means of slots and lugs, or their equivalents, all substantially as specified and shown, for the object set forth.

2. In a harrow or cultivator, a combined colter and mold-board tooth or share, the upper half of which presents a convex semicircular thin colter edge to the soil, and. the lower half being twisted and its point bent forward, forming and presenting to the soil a concave semicircular mold-board, the two rear corners of the cutting-point of which are on a level plane with each other, and said point, when working, is located in the rear of the end of the share, connecting with the spring, all substantially as set forth, for the purposes specified.

3. In a harrow or cultivator, an oscillating sharesupporting spring having slots E and lugs D, or their equivalents, in combination with a tooth or share the upper end of which has circular indentures N N, formed in its edges, which roll on or engage said lugs or equivalents, all substantially as specified and shown.

4. The combined oscillating spring and shoe, in combination with the combined colter and share, forming a connection therewith, for the purpose set forth.

G. EDWIN DUNBAR.

Witnesses:

AMos D. ALLEN, G. M. GATES. 

